I could not agree less. I would have considered the PA with NBL material. May be NBL prevented ERHC from making it public. As far as I know NBL did not make it public either. On the other side disclosing a material event is a legal obligation, so a confidentiality clause could never have prevented them from disclosing.
Please note that the block 4 monies were received in feb 2006. Nevertheless the full amount should have been reported as a receivable in the accounts in the 10q for the first quarter.